1. Technical Field
The present disclosure relates to a light emitting device and a method of manufacturing the same.
2. Description of Related Art
Semiconductor light emitting elements such as light emitting diodes (LEDs) and laser diodes (LDs) are used as various kinds of light sources. Particularly in recent years, as illumination light sources replacing fluorescent lamps, light emitting diodes are receiving attention as next-generation lighting, due to their small power consumption and long life. Still, further improvements in light emission output and in light emission efficiency are needed for the light emitting diodes. For example in the field of light sources including vehicular headlights and projector lighting, there is also a need for light sources that exhibit high luminance and have a particular light distribution, e.g., a hemispherical light distribution called Lambertian. There has been proposed a light emitting device in which lateral surfaces of a light emitting element are covered with a light reflecting member for the purpose of attaining high front luminance. Light emitting devices are required to maintain their performance over a long period of use, particularly in interior and exterior illumination of vehicular applications.
As such, a light emitting device has been described in which lateral surfaces of a light emitting element is covered with a light reflecting member. For example, Japanese Unexamined Patent Application Publication No. 2009-218274 discloses a semiconductor light emitting device that includes: a light emitting element; a wavelength conversion layer positioned on or above the light emitting element; a reflecting member disposed adjacent to a lateral surface of the wavelength conversion layer and to a lateral surface of the light emitting element, the lateral surface of the light emitting element being positioned on an identical surface side to the lateral surface of the wavelength conversion layer; and a base member on which the light emitting element and the reflecting member are mounted. The light emitting device has a structure in which the lateral surface of the wavelength conversion layer (e.g., a light-transmissive member) and the lateral surface of the light emitting element are covered with the reflecting member (e.g., a light reflecting member) formed to surround the wavelength conversion layer.
Further, Japanese Unexamined Patent Application Publication No. 2012-79840 discloses a light emitting device that includes: a base member; at least one light emitting element mounted on the base member; a resin layer disposed on the light emitting element; a plate-like member mounted on the resin layer; and a reflecting resin member provided to surround the resin layer and the plate-like member. The reflecting resin member covers the entire lateral surface of the plate-like member. The light emitting device has a structure in which the lateral surface of the resin layer (i.e., the light-transmissive member) and the lateral surface of the plate-like member are covered with the reflecting resin member (i.e., the light reflecting member) formed to surround the resin layer.
With the light emitting devices disclosed in Japanese Unexamined Patent Application Publication No. 2009-218274 and 2012-79840, the reflecting member at the lateral surface of the light emitting element may deteriorate over a long period of use.